Ok I'm going to dispel a few myths here.
Higher Octane = LESS bang. The whole point of higher octane is to prevent detonation at high compression.
Lower octane fuel cant be compressed as much before it detonates, which is the direct cause of engine knocking.
Now....what octane do you need? let me start with the I4s since thats easy. The 5S and 2AZ both take regular gas. You gain nothing by using higher octane fuel. You dont get more power, you dont get more mileage, it doesn't "clean your engine better", nothing. The engines doesnt compress the fuel enough for it to detonate before full compression, so 87 is just fine.
Now for the V6s, the compression is higher, and its premium recommended. What this means is that testing was done with premium gas on that engine. What happens if you put regular in? The ECU in all modern cars are smart enough to retard timing when it first senses early detonation. Retarded timing does mean reduced power, and possibly reduced mileage. Its important to note that this will NOT harm the engine in any way.
Whether or not this difference in mileage is enough to make up the difference in price, I dont know since I havent seen raw data about how much mileage decreases when running regular on a premium recommended engine. I'll reserve judgement until someone draws up some real data, but my guess is on the 1MZ/3MZ, its not all that much, since its not a extremely high compression/forced induction engine, and you would still save money by filling up on regular than filling up with premium at a ~15% premium.
And finally..the 2GR. Im pretty sure the 2GR-FE, in all its Toyota variants (Avalon, Camry, Rav4) is rated for regular gas and not premium gas. Toyota.com doesnt say, Edmunds says regular, and In the Lexus variants (ES350, RX350), it produces more power and is rated for premium, probably due to advanced timing for premium gas.
Its kind of suprising because its high output and high compression at 10.8, but what I'm thinking is toyota took it easy with the timing on the 2GR at the expense of some horsepower in the Toyotas, enough so that regular gas was all thats necessary.
onefiend - Can you verify if the 07 Camry V6 is premium recommended or not? If its not premium recommended, then theres no benefit to using premium on the 2GR-FE in Toyotas either.
My recommendation is use regular if your on a budget on the I4 or V6, and use premium if your not living paycheck to paycheck and have a 1MZ/3MZ V6. I'm not entirely sure how ECU engine timing adjustments play with forced induction, so this recommendation is only for N/As. If you have enough money to afford a turbo or S/C, then you have enough money to afford premium gas and you shouldnt put anything else in your engine.
Higher Octane = LESS bang. The whole point of higher octane is to prevent detonation at high compression.
Lower octane fuel cant be compressed as much before it detonates, which is the direct cause of engine knocking.
Now....what octane do you need? let me start with the I4s since thats easy. The 5S and 2AZ both take regular gas. You gain nothing by using higher octane fuel. You dont get more power, you dont get more mileage, it doesn't "clean your engine better", nothing. The engines doesnt compress the fuel enough for it to detonate before full compression, so 87 is just fine.
Now for the V6s, the compression is higher, and its premium recommended. What this means is that testing was done with premium gas on that engine. What happens if you put regular in? The ECU in all modern cars are smart enough to retard timing when it first senses early detonation. Retarded timing does mean reduced power, and possibly reduced mileage. Its important to note that this will NOT harm the engine in any way.
Whether or not this difference in mileage is enough to make up the difference in price, I dont know since I havent seen raw data about how much mileage decreases when running regular on a premium recommended engine. I'll reserve judgement until someone draws up some real data, but my guess is on the 1MZ/3MZ, its not all that much, since its not a extremely high compression/forced induction engine, and you would still save money by filling up on regular than filling up with premium at a ~15% premium.
And finally..the 2GR. Im pretty sure the 2GR-FE, in all its Toyota variants (Avalon, Camry, Rav4) is rated for regular gas and not premium gas. Toyota.com doesnt say, Edmunds says regular, and In the Lexus variants (ES350, RX350), it produces more power and is rated for premium, probably due to advanced timing for premium gas.
Its kind of suprising because its high output and high compression at 10.8, but what I'm thinking is toyota took it easy with the timing on the 2GR at the expense of some horsepower in the Toyotas, enough so that regular gas was all thats necessary.
onefiend - Can you verify if the 07 Camry V6 is premium recommended or not? If its not premium recommended, then theres no benefit to using premium on the 2GR-FE in Toyotas either.
My recommendation is use regular if your on a budget on the I4 or V6, and use premium if your not living paycheck to paycheck and have a 1MZ/3MZ V6. I'm not entirely sure how ECU engine timing adjustments play with forced induction, so this recommendation is only for N/As. If you have enough money to afford a turbo or S/C, then you have enough money to afford premium gas and you shouldnt put anything else in your engine.

2000 Black Solara SE
- Jon11582
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